buyer beware.. eyes' wide open, and I suggest you read wellys thread/experience and make your own mind up
Wellys was awefull in reliability terms unfortunately
others run them and they have been luckier.
other note: they are larger outlet diameter than the std k04 gaskets, so std gasket will overhang, and burn/fail, passing by the turbine next. I dont know of an available gasket for this oversized hole. They offer ceramic coated one.. dont risk a non coated one.. BUT, if they are made from the same material as Wellys was, it was very low grade cast iron, and not rated to 900'c operating temps....... hence the multiple cracks in only 3 weeks use. It was a shame as performance was most certainly gained from it.